Mortality and Risk Factors in Very Elderly Patients Who Start Hemodialysis: Korean Renal Data System, 2016-2020

Introduction: The number of elderly patients with end-stage renal disease (ESRD) is increasing worldwide. However, decision-making about elderly patients with ESRD remains complex because of the lack of studies, especially in very elderly patients (>= 75 years). We examined the characteristics of very elderly patients starting hemodialysis (HD) and the associated mortality and prognostic factors. Methods: Data were analyzed retrospectively using a nationwide cohort registry, the Korean Renal Data System. Patients who started HD between January 2016 and December 2020 were included and divided into three groups according to age at HD initiation (<65, 65-74, and >= 75 years). The primary outcome was all-cause mortality during the study period. Risk factors for mortality were analyzed using Cox proportional hazard models. Results: In total, 22,024 incident patients were included with 10,006, 5,668, and 6,350 in each group (<65, 65-74, and >= 75 years, respectively). Among the very elderly group, women had a higher cumulative survival rate than men. The survival rate was lower in patients with vascular access via a catheter than in those with an arteriovenous fistula or graft. Very elderly patients with more comorbid diseases had a significantly lower survival rate than those with fewer comorbidities. In the multivariate Cox models, old age, cancer presence, catheter use, low body mass index, low Kt/V, low albumin concentration, and capable status of partial self-care were associated with high risk of mortality. Conclusion: Preparation of an arteriovenous fistula or graft when starting HD should be considered in very elderly patients with fewer comorbid diseases.